The 2S4 has been in service with the Russian Forces since the mid 1970’s and still remains the largest calibre self propelled mortar to date.
The base plate is lowered to the ground, the barrel separates from its vertical firing position and flips into a horizontal position so the breech is in line with a small conveyer which runs along the top of the vehicle. Rounds are lifted on to the conveyor via a small crane which then transfers the round in to the breach where the crewman pushes it in. The barrel flips back into the firing position on the base plate and is then fired by the crew. The barrel has a limited traverse of 10 degree’s from left to right.
It can fire up to 9650m, dropping a High Explosive 240mm round with a great level of accuracy and lethality. This was demonstrated in the Soviet War in Afghanistan and the first Chechen war by Russia.
The main vehicle is a modified GMZ mine laying vehicle. The mortar is based on the towed M240 mortar, which entered service in the 1950’s.
The engine is front right of the vehicle with the driver to its left, with the commander behind him and a rear compartment for the ammunition and remaining 2 crew. A ammunition supply vehicle with 5 crewman also accompanies the vehicle.
It goes by several names. The West call it the M1975 as it was first spotted in 1975. Its Russian designation is SM-240 (2S4) and amongst troops, the Tyulpan or Tulip Tree. Its believed the vehicle is now just held in reserve.